HR: 17:40h
AN: OS12C-07    [PDF]
TI: On the Construction of Reanalysis Argo Dataset Using a 4DVAR Data Assimilation System
AU: * Qin, J
EM: jiang@jamstec.go.jp
AF: Frontier Observational Research System for Global Change, 3173-25, Showa-machi, Kanazawa-ku, Yokohama-city, Kanazawa, Yokohama, 236-0001 Japan
AU: Toshiyuki, A
EM: awaji@kugi.kyoto-u.ac.jp
AF: Kyoto University, Oyiwake-cyo, Kitashirakawa, Sakyo-ku, Kyoto, 606-8502 Japan
AU: Toshiyuki, A
EM: awaji@kugi.kyoto-u.ac.jp
AF: Frontier Research System for Global Change, 3173-25, Showa-machi, Kanazawa-ku, Yokohama-city, Kanazawa, Yokohama, 236-0001 Japan
AU: Nozomi, S
EM: nsugiura@jamstec.go.jp
AF: Frontier Research System for Global Change, 3173-25, Showa-machi, Kanazawa-ku, Yokohama-city, Kanazawa, Yokohama, 236-0001 Japan
AU: Shuhei, M
EM: smasuda@jamstec.go.jp
AF: Frontier Research System for Global Change, 3173-25, Showa-machi, Kanazawa-ku, Yokohama-city, Kanazawa, Yokohama, 236-0001 Japan
AU: Hiromichi, I
EM: higarashi@jamstec.go.jp
AF: Frontier Research System for Global Change, 3173-25, Showa-machi, Kanazawa-ku, Yokohama-city, Kanazawa, Yokohama, 236-0001 Japan
AU: Kensuke, T
EM: takeuchik@jamstec.go.jp
AF: Frontier Observational Research System for Global Change, 3173-25, Showa-machi, Kanazawa-ku, Yokohama-city, Kanazawa, Yokohama, 236-0001 Japan
AU: Nobuyuki, S
EM: nshikama@jamstec.go.jp
AF: Frontier Observational Research System for Global Change, 3173-25, Showa-machi, Kanazawa-ku, Yokohama-city, Kanazawa, Yokohama, 236-0001 Japan
AB: The Argo program is known as a major component of the ocean observing system. It will measure the upper layer profiles of temperature and salinity by a global array of 3,000 profiling floats. When the Argo float network is completed, 100,000 profiles of temperature and salinity will be reported every 10 days. The Argo data will provide a quantitative description of the evolving state of the upper ocean and patterns of ocean climate variability. The in-situ Argo data, however, can only give us discontinuous information on the ocean state, since the Argo float is a floating buoy and the sampling time and position vary continuously. Therefore, it is necessary to create a 3-dimensional grid dataset from the sparsely measured Argo data for the effective use of the observational data. To make such a physically integrated Argo dataset, we developed a 4DVAR data assimilation system, which is constituted on the basis of MOM3 and its adjoint by using 4-dimensional variation method, and tried to apply it to the Argo data. An experiment was carried out, in which the assimilation duration was set as 2 year from 2001 to 2002, and a global ocean model with the resolution of 1x1 deg. in horizontal and 36 levels in vertical was used. The 22 years of simulation beginning from 1980 was firstly conducted by using the sea surface heat flux, fresh water flux, and wind stress of the NCEP reanalysis data. Then, we started the assimilation by using the profiles of temperature and salinity obtained with the Argo float during 2001 to 2002. Comparisons of the results with and without the Argo data revealed that both fields of temperature and salinity are significantly improved by the Argo data. Meanwhile, results of the volume transport and heat transport are also reasonable. Further study is still needed for the operational use of this assimilation system.
DE: 4200 OCEANOGRAPHY: GENERAL
DE: 4255 Numerical modeling
DE: 4263 Ocean prediction
SC: Ocean Sciences [OS]
MN: 2003 Fall Meeting